# 作者：小七
# 2024年12月27日
# 1
a = [1, 1, 2, 2, 3, 4, 4]
i = 0
while i < len(a):

    if a.count(a[i]) == 1:
        print(a[i])
    i += 1
# 2
for j in range(1, 21):
    print(j, end=" ")


# 3

def say_hello(n):
    """
        具体打印几次依靠传递的参数
    """
    for k in range(int(n)):
        print("hello")


n = input()
say_hello(n)

# 4

import wd5

wd5.print_line()

# 5

my_list = [x for x in range(10)]
print(my_list)
my_list.sort()
print(my_list)
my_list.sort(reverse=True)
print(my_list)
my_list.reverse()
print(my_list)

# 6

a = [1, 1, 2, 3, 3, 4, 5, 5]
i = 0
while i < len(a):

    if a.count(a[i]) == 1:
        print(a[i])
    i += 1
